Space: 1999 - Season 1, Episode 11: Guardian of Piri
Trailer
In an attempt to save the day, John Koieng, a young courageous commander for the Moonbase Alpha, who after the horrible explosion that takes the moon out of its orbit, struggles against solving that disaster, while investigating on the matter, the thing that challenges him, as he is shocked by revealing the truth, so he makes a unity with the whole crew.